单项选择题
A.①②③④ B.③④ C.①③④ D.①②④
A.材料性质 B.荷载 C.构件截面尺寸 D.支座位移
A.114.239m,1/3360 B.114.239m,1/6720 C.114.256m,1/3360 D.114.222m,1/6720